Question

Casparian strips occur in

• A. Longitudinal and radial walls of epidermal cells
• B. Longitudinal walls of xylem
• C. All walls of endodermis
• D. Radial and tangential walls of endodermis

Answer 1

The correct option is D Radial and tangential walls of endodermis

Casparian strip is a band of cell wall material deposited on the radial and tangential walls of the endodermis and is chemically different from the rest of the cell wall, the cell wall being made of lignin and without suberin, whereas the Casparian strip is made of suberin and sometimes lignin. It blocks the passive flow of materials such as water and solutes into the stele of a plant. It varies in width and is often much narrower than the wall in which it occurs. It is typically located closer to the inner tangential wall than the outer.